On Mon, Mar 12, 2012 at 01:14:10PM +0200, Gleb Natapov wrote: > On Mon, Mar 12, 2012 at 11:35:29AM +0200, Michael S. Tsirkin wrote: > > Before we start tweaking and enhancing hardware, I think > > it makes sense to document what we currently have, to make > > sure we stay compatible. > > This documents the hotplug interface for piix. > > Stubs for cpu hotplug, PM. > > > We already have docs/specs/acpi_pci_hotplug.txt, no?
Indeed. I didn't notice it. Alex, so if you change this device you probably want to update the spec :) > > Signed-off-by: Michael S. Tsirkin <m...@redhat.com> > > --- > > docs/acpi.txt | 32 ++++++++++++++++++++++++++++++++ > > 1 files changed, 32 insertions(+), 0 deletions(-) > > create mode 100644 docs/acpi.txt > > > > diff --git a/docs/acpi.txt b/docs/acpi.txt > > new file mode 100644 > > index 0000000..4938d48 > > --- /dev/null > > +++ b/docs/acpi.txt > > @@ -0,0 +1,32 @@ > > +QEMU exposes the following registers to guests, > > +intended primarily for use by the ACPI interface. > > + > > +PCI Hotplug > > +---- > > + > > +Events use the standard GPE register: > > +GPE 0xafe0 - an ACPI GPE register > > + > > +Hotplug events set GPE bit 1 (mask 0x2) > > + > > +The following registers are used for PCI hotplug. > > +Each register is 32 bit (4 bytes) long, and has little endian format. > > +Bits 0-31 in each register correspond to slots 0-31 on the root bus, > > +respectively. > > + > > +UP 0xae00 - RO - Bit set by host on device insertion (note:existing > > implementations > > + trigger device check event) > > +DOWN 0xae04 - RO - Bit set by host on user eject request > > +EJ0 0xae08 - WO - Bit set by guest removes all power to device > > +RMV 0xae0c - RO - Bit set by host if slot supports hotplug > > + (can not change while guest is up) > > + > > + > > +Power management > > +---- > > +TODO > > + > > + > > +CPU hotplug > > +---- > > +TODO > > -- > > 1.7.9.111.gf3fb0 > > -- > Gleb.
